Longitudinal Word-List Decline at a Memory Center
You are a clinical research coordinator at an Alzheimer's disease research center. A 72-year-old retired teacher is in a longitudinal memory study. One year ago she recalled 8/15 words after a 20-minute delay on a 15-word list-learning task and recognized 14/15 with one false positive. Today, using the same list and the same 20-minute filled delay, she recalls 4/15, recalls 6/15 with category cues, and on recognition endorses 11/15 targets with four false positives to semantically related lures. She completed the intervening cognitive tasks without difficulty and denies feeling depressed; her score on a depression screen is 3/15. Her daughter reports repeated questions about appointments and one missed utility payment. You must decide whether this is normal age-related forgetting, a retrieval deficit, an encoding problem, or something more concerning, and how to present it without diagnosing.
1. Compare the two time points. What does the pattern of free recall, cued recall, and recognition with semantic false positives suggest about the stage of memory affected?
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The one-year drop from 8 to 4 on delayed free recall exceeds normal practice or age effects on the same instrument, so it is a real decline. Cueing adds only two words, which argues against a pure retrieval deficit: retrieval problems usually improve substantially with cues or recognition. Recognition is also impaired at 11/15 and is accompanied by four semantic false positives, which suggests the words were encoded shallowly or the memory trace is degraded and gist-based, so related lures feel familiar. That pattern points to encoding or consolidation, consistent with medial temporal involvement, rather than to attention or depression. It does not by itself confirm a diagnosis: recognition is still above chance, and the profile could occur in mild cognitive impairment. The defensible statement is "decline in delayed recall and recognition with gist-based errors," not "Alzheimer's disease."
2. What additional information would you need before the team classifies this as more than normal forgetting? Name at least four domains.
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- Functional change: the daughter's report is a start, but quantify it, including missed appointments, medication errors, financial mistakes, and driving. 2) Other cognitive domains: executive function, processing speed, language, and visuospatial ability; a single word-list score is not a cognitive profile. 3) Informant-based longitudinal history and, if available, prior neuroimaging or biomarker status, interpreted by the clinician rather than the coordinator. 4) Rule-outs: depression (screen is low but not definitive), sleep apnea, thyroid disease, B12 deficiency, medications with anticholinergic load, alcohol use, and hearing loss. 5) Effort and test conditions: same examiner, same time of day, same list version? A change in version or setting can create a spurious decline. 6) Practice effects: repeated exposure to the same list can inflate scores, so a drop is more, not less, concerning. Only after these are assembled can the team judge whether the change meets criteria for mild cognitive impairment.
3. How would you communicate these results to the participant and daughter without making a diagnosis, and what follow-up would you recommend?
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Use plain, non-diagnostic language: "Your scores today are lower than last year's, especially for remembering a list after a delay. That can happen for many reasons, including sleep, mood, medications, and changes in thinking. It does not by itself mean you have Alzheimer's disease. The doctor will look at the whole picture." Avoid the words "dementia" or "probable AD" in a coordinator role; refer to the study clinician. Recommend repeat testing in 6-12 months with the same instrument and, if the protocol allows, a clinical evaluation sooner given the functional report. Give the daughter a concrete functional checklist to complete before the next visit. Document that cues and recognition were administered, because that is what distinguishes retrieval from encoding. Offer the participant a written summary and a contact for questions; do not leave the family with a score alone.